The European Commission has approved an expanded indication for Amgen Inc.’s Blincyto, a drug to treat acute lymphoblastic leukemia.

The Thousand Oaks biotech’s drug helps the body’s immune system target cancer cells, including the few cells that remain in a human body during treatment, called minimal residual disease. MRD occurs when there are cancer cells present even though the patient has achieved complete remission by conventional assessment.

The indication expansion means adult patients with acute lymphoblastic leukemiawith an MRD greater than or equal to 0.1 percent can now use Blincyto. In March 2018, the U.S. Federal Drug Administration approved Blincyto for the treatment of adults and children with B-cell precursor ALL with MRD greater than or equal to 0.1 percent.

“This approval represents a paradigm shift in the management of ALL in the European Union, making Blincyto the first and only treatment with marketing authorization to include the presence of MRD,” said Dr. David Reese, executive vice president of research and development at Amgen.

Shares of Amgen (AMGN) closed Tuesday down $1.90, or nearly 1 percent, to $201.98 on the Nasdaq.